Within the field of metal cutting tools used in milling operations, cutting inserts removably securable in a cutting body have long since provided a suitably hard material, i.e. cemented carbide, in the vicinity of the cutting edge, where the cutting body, manufactured from a less hard material, is reusable following the disposal of a worn or damaged cutting insert.
Many cutting inserts of this type are seated in insert receiving pockets of the cutting body which provide support for the cutting inserts in both axial and radial directions, e.g. slot milling and face milling operations, although in some applications, e.g. extended flute mills and porcupine cutters, the cutting body may not support the cutting inserts in an axial direction.
US 2007/0286692 discloses a milling tool comprising a toolholder having a plurality of insert receiving pockets, each insert receiving pocket housing an indexable cutting insert removably secured by means of a clamping screw.
Each of the insert receiving pockets includes a seat surface having a threaded hole for receiving the clamping screw, and a side abutment surface having axially and radially facing abutment portions for supporting the cutting insert in both axial and radial directions.
Each cutting insert has a clamping hole including a clamping surface defining at least part of a non-circular, substantially elliptical cone, and each clamping screw, extending through the clamping hole, includes a substantially cone shaped clamping head contacting the clamping surface at two contact points.
The resultant clamping force applied at the two contact points is directed towards both the radial and axial facing abutment portions.
U.S. Pat. No. 5,542,793 discloses a spiral-toothed milling head comprising a tool body having four spiral clamping grooves, each spiral clamping groove fitted with a plurality of square or parallelogram-shaped indexable cutting inserts overlapping in an axial direction.
Each cutting insert is removably secured to its respective spiral clamping groove by means of a clamping screw, the cutting insert being seated on an insert reception seat having a radially facing abutment surface but no axially facing abutment surface.
Each cutting insert has an essentially cylindrical bore therethrough with a slightly convexly bowed conical end portion, and each clamping screw includes an essentially conical shaped clamping head and a precisely formed cylindrical portion extending through the cylindrical bore.
The essentially conical shaped clamping head engages the slightly convexly bowed conical end portion, and the precisely formed cylindrical portion fits into a cylindrical, accurately positioned matching fitting bore in the insert reception seat, whereby the axis of the cylindrical bore is offset from the axis of the fitting bore. The clamping screw, itself, provides support for its respective cutting insert in the axial direction.